import { detect } from "@antfu/ni"

export async function getPackageManager(
	targetDir: string,
	{ withFallback }: { withFallback?: boolean } = {
		withFallback: false,
	},
): Promise<"yarn" | "pnpm" | "bun" | "npm" | "deno"> {
	const packageManager = await detect({ programmatic: true, cwd: targetDir })

	if (packageManager?.startsWith("yarn")) return "yarn"
	if (packageManager?.startsWith("pnpm")) return "pnpm"
	if (packageManager?.startsWith("bun")) return "bun"
	if (packageManager?.startsWith("deno")) return "deno"
	if (packageManager?.startsWith("npm")) return "npm"

	if (!withFallback) {
		return "npm"
	}

	const userAgent = process.env.npm_config_user_agent || ""

	if (userAgent.startsWith("yarn")) {
		return "yarn"
	}

	if (userAgent.startsWith("pnpm")) {
		return "pnpm"
	}

	if (userAgent.startsWith("bun")) {
		return "bun"
	}

	return "npm"
}

export async function getPackageRunner(cwd: string) {
	const packageManager = await getPackageManager(cwd)

	if (packageManager === "pnpm") return "pnpm dlx"

	if (packageManager === "bun") return "bunx"

	return "npx"
}